The present invention relates to an adaptive cruise control system which executes a cruise control for maintaining a set vehicle speed and a following control for following a preceding vehicle ahead of the host vehicle while keeping a set inter-vehicle distance.
Japanese Patent Provisional Publication No. 2001-171389 discloses an adaptive cruise control system which is arranged to calculate a target vehicle speed on the basis of an inter-vehicle distance between a host vehicle and a preceding vehicle ahead of the host vehicle and to execute a cruise control on the basis of the target vehicle speed so that the host vehicle travels while following the preceding vehicle.